Tuesday
December 18th 2007, 14:00
CCC
conference room 874/1-011
The
minutes of the previous meeting were circulated by Frank. Few comments have
been incororporated already. No further comments brought up today.
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Stefano replaces Frank as a scientific secretary.
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Additional topics: injection dry-run by Mike.
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Alick asked whether we will get a summary of what comes out of the LHC access
scheduled for W2 of 2008. Magali agreed to report on it on the LHCCWG of
January 15th.
Brennan
reported on the 2007 beam commissioning of the LSS4/LSS6 and TT40/TT60. His
presentation was mainly focused on the organisational aspect of the tests
rather than on the technical results, which were already reported at the LTI
and LTC meetings. Brennan reminded that this year we had high intensity
extractions in TT40 (already done in 2004 and 2006) and in TT60 (done for the
first time) and tests of the interleaved extraction scheme. This was achieved
in two MD days on August 1st and September 26th. Brennan
was in charge of the overall test coordination within the AB-BT mandate. AB-OP
managed the various dry-runs and machine checkouts and dealt with scheduling
issues. The beam tests were organised through dedicated monthly coordination
meetings that started about 6 months before the first beam test (similar to
2006 but corresponding to a total investment of about three times less than for
the first extraction tests in 2003). The documentation of the tests
(objectives, plans and schedule, actions and people responsible for them,
procedures, ...) was web-based (see the LTI project page). This
approach proved to be sufficient for these tests covering fairly simple systems
however Brennan thinks that it might not be adequate for the organisation of
the commissioning of more complex inter-dependant systems: we will need more
for the LHC.
Brennan
reminded that the schedule of the extraction tests was changed three times
during the year. This posed organizational problems in particular to
accommodate the required time for the dry-runs, which in fact could have been
performed better. Brennan proposed that in the future the dry run scheduling be
improved (and become ‘official’), and that a few hours of real MD time should
be allocated for the dry-runs because often the required activities cannot be
carried out parasitically with other machine activities.
Next,
Brennan listed the achievements versus expectations for the two MD days. In
general, the test program was followed without major problems and the main
goals were achieved. Beam tests were performed without contingency, which
prevented to address any test initially marked as "optional" or
second priority. Several minor interlocking and technical issues were found, as
summarized at pages 12th and 13th of Brennan's slides.
Thijs
asked about the radiation damage experienced by the BTV acquisition boxes. Do
we have the same technology in the LHC? Brennan replied that apparently the
electronics was already degraded by previous high-intensity fixed target
resonant extractions. The BTV gave good response after repairing the boxes.
Jean-Jacques commented that for the first year of operation we will use non radiation-hard
cameras and react according to experience.
On
general organisation issues, Brennan commented that the dry-runs are still
crucial for the beam commissioning tests. For 2008 it is not clear yet how
these tests will have to be coordinated (OP or HWC?). It is not clear either
how coordinators, system commissioners, EiC's, CiC's and HWCiC's will work
together on the LHC beam commissioning. For these tests, it helped to have
clear and simple responsibilities assigned to the various people involved.
Brennan stated that the only significant participation to the extraction tests
from OP/LHCCWG came from the "usual suspects" already working on
extraction and interlocking. There had been a few attempts from BT to include
other people, but these had not succeeded because the bases were well covered.
The
outstanding things to do for/in the 2008 are the hand-over of the SPS
extractions from BT to OP; the SPS to LHC transfer line (re-)commissioning with
high intensities; the commissioning of LHC injection systems, LHC beam dump
system and the LHC MKQA system. In the conclusive remarks, Brennan re-iterated
that a better (wider and more systematic) coordination (possibly a "real
time" follow up) will be needed for 2008 in order to move efficiently into
the "operational phase". It is not clear how this will be done.
Jean-Jacques
commented that dry-runs need to be very well coordinated in order to be
efficient. Owners of sub-system cannot decide by themselves when to perform the
tests but we need instead a strict overall coordination (we could for example
fix early on proposed dates for the tests). Further discussion on this issue
was postponed until after Jan presentation.
Jan
discussed organisational aspects of the TI2 beam commissioning. A recent
overview of the physics outcome of the tests was presented by Jan at the LTC
of Dec. 5th. Jan reminded that this year TI2 was successfully
commissioned with beam during one MD of 22 hours on October 28th.
The first shot reached the end of the line! The beam was sent on a temporary
beam dump installed about 50 meters upstream of the nominal TED because due to
radio protection constraint it was decided not to irradiate the region close to
the LHC tunnel. This had the side effect of cutting out relevant BI for the
beam diagnostics at the end of TI2 (BCT, BTV), which to some extent jeopardized
tests that were foreseen. Jan reminded that further tests on TI2 and the
re-commissioning of TI8 were initially foreseen but were then cancelled due to
conflicts with the LHC HW commissioning.
The
TI2 HW commissioning was followed up daily by Nicolas Gilbert. Jan acknowledged
Nicolas' good work and listed various issues that were encountered and solved.
Jan himself stepped into the activity when the dry-run started and followed up
the coordination of the beam tests. Jan stressed that he and Volker ended up
looking after many issues that were not within the LTI project mandate. A few
examples (see slide number 4 of Jan's presentation): organization/coordination
of access tests; INB issues related to the temporary shielding installed in
PMI2; organization of the patrol to close the ALICE cavern; discussions with
ALICE and LHC HW coordination to minimise the impact of the TI2 tests on other
ongoing activities. This was not an ideal situation because they had to invest
much more time than foreseen in this coordination activity. Various critical
issues (in particular the topics related to safety and radiation aspects)
should not be under the responsibility of BT and Jan suggested that in the
future someone else should be in charge of the global test coordination. He
acknowledged that in many cases the progress of the various activities relied
on the good will of people who worked outside the normal working hours but this
situation cannot continue. On the other hand, the coordination of the beam
tests proper required a much more reduced coordination effort by Jan because the
planning of the various beam tests was left in the hands of the people
responsible for each task/measurement. This worked out very well but again may
not be adequate at the scale of the LHC.
The
planning of the various activities ongoing in parallel for the preparation of
the TI2 beam tests was followed-up through a web page updated regularly
(several times per day) by Jan (see link).
This was sufficient for this relatively small coordination activity but Jan
believes that we will need something more for the LHC. Reyes commented that a
web-based planning tool is being prepared for the SPS and LHC by Eric Veyrunes.
The experience gained during the TL coordination should be used to improve
these tools.
Jan
mentioned briefly some highlights of the beam tests (see link
for more details). Two hardware-related problems were encountered: overheating
of the MBIAV magnet circuit (which required an on-line change of the SPS cycle
to reduce the duty cycle) and an inversion of two pairs of correctors
(corrected in the software during the MD). Nevertheless, the basic program was
completed and many measurements could be successfully performed. The physics
outcome of the beam tests was jeopardized by the missing instrumentation at the
end of the line and also by the fact that a second MD day was cancelled. Many
outstanding measurements (detailed optics measurements, precise collimator
beam-based set-up, aperture measurements high-quality data taking for screen
matching and commissioning of higher beam intensities and multi-bunches) will
therefore have to be done in 2008. During the shut-down period many outstanding
issues for TI2 and TI8 will be followed up under the responsibility of Nicolas
Gilbert (detailed to-do list at page 11).
The
organisational requirements during 2008 will be similar to this year however a
closer collaboration with the experiments and with the LHC HW coordination will
be needed to prepare a more global planning, possibly in combination with the
preparation of a the sector test. Jan suggests that a dedicated body should
coordinate globally the various activities, from the dry-run to the beam tests.
Roles and responsibilities need to be defined.
Picking
up also the issues brought up by Brennan, Roger commented that we clearly need
an overall planning for 2008 in order for OP to step into the cold-checkout and
beam commissioning. A first OP internal workshop was held a few weeks ago and
addressed the readiness of the various systems. As a follow-up of this, at the
beginning of 2008 we will have another discussion that will also involve the
experts for the various systems. The LHCCWG should be the forum for these
discussions. The idea is that a small team of 3 or 4 people will be assigned to
the preparation and overall organization of the checkout and will report to the
LHCCWG. The details of this activity and the people involved will be worked out
early on in 2008.
Thijs
asked if the cryogenics will also be looked after. Roger replied that this
aspects is closely related to the powering tests and we will have to assume
that the main deliverable of the HWC will be to provide working circuits. There
will be no need for us to follow up directly the cryo commissioning.
Mike
discussed the main achievements of the LHC injection dry-run that took place on
Friday, Dec. 14th and Monday, (Dec. 17th). The detailed
program of the dry-run is available at this webpage (Mike's
docs), which is also updated with the information on status/readiness of
the various systems. Mike acknowledged the contribution of the many people who
contributed to these tests, in particular Reyes and Verena. The main goal for
this test was to drive all the main accelerator components from the controls
room in a coherent way by using appropriate high level application software.
Mike commented that this goal was basically achieved. This first test has to be
considered a very useful exercise and Mike welcomed the good progress of the
various systems (see below). He believes that similar tests should be organized
on a regular basic in 2008 (not too often, though, to avoid waisting too many
resources). Next, Mike briefly outlined the statuses of the various
sub-systems.
The
successful set-up of the required timing structure was an important
milestone for this dry-run: all the required pieces came together into play and
we could drive the kickers in 2 and 8 and most of the relevant instrumentation.
Fixed displays were available for the simulated slow BCT signal
(Jean-Jacques commented that the fast BCT is also ready however he was not
informed of the dry-run otherwise he would have prepared something). Capture
and data concentration for the BPM's were also working well. YASP
was used very successfully for settings, threading and injection steering. Screen
acquisition is also basically ready (in the dry-run we used the same tools
already developed for the SPS transfer lines). Instead, for the BLM
acquisition and fixed display a lot of work remains to be done. Next Mike
acknowledged a very good success for the collimator control. Stefano
commented that we could automatically drive through the LHC sequencer a
collimator to follow predefined discrete settings for the TDI (parking, coarse,
nominal settings defined within different machine modes). Settings were sent to
a collimator prototype in the collimator workshop and not to the TDI in the
tunnel that is not yet ready for movements. The power converters were
also under control: a group of 200 converters was automatically driven by the
sequencer through the various machine modes (simulation mode: no current sent
into the magnets). The LSA functionality for the setting generation and FiDeL
worked very well. The drive functionalities of the various systems were carried
out with a first version of the LHC sequencer put in place for the
dry-run. Reyes commented that we executed the nominal LHC injection sequence:
all the required tasks were defined in appropriate database tables and executed
sequentially to drive all the relevant hardware. Responding to a question by
Jean-Jacques, Reyes stated that for these tests we used the CO sequencer
developed by Vito Baggiolini's team for the LHC HWC. Ralph S. suggested that
the results of the various sequence tasks should be logged and made available
to other users. Reyes commented that work is ongoing in this direction.
Mike
also commented on the first deployment of RBAC (Role-based access). This
is clearly a critical software for the LHC and will need more testing. In
particular, we need to define a strategy for the definition of roles (user
based or OP team based?) and for the configuration of the system (for example,
how long after login the token expires?). During the dry-run test a first
version was deployed for the power converters. Work is ongoing for the other
systems. Jean-Jacques warned that all the concerned applications need to be
RBAC-aware very early on otherwise it will be very difficult to run them in a
RBAC environment. He also commented that there are still a few functionalities
that are not yet provided by RBAC, like for example the machine mode awareness,
the dynamic change of roles and the interface between various machine (RBAC is
defined per FESA class and hence the classes that control equipment in
different machines need careful treatment).
Brennan mentioned that the dry run
tests for the LHC beam dump system are already being prepared by the LBDS project
with OP and HWC, to start in week 7, and that a general coordination forum is
needed.
Gianluigi commented that in the future it would be good to
involve the commissioners in this kind of exercises. The CiC's
could be "used" to test the available tools and could at the same
time get familiar to what will will used for the LHC
commissioning. Mike promised that for the next tests more people will be
involved.
Tuesday
January 15th, 14:00
CCC conference room
874/1-011
Provisional
agenda:
Minutes of
previous meeting
Matters arising
Experimental dipoles and
compensators at injection (Massimo)
Access system tests (Magali)
Status of procedures (Roger)
Activities in 2008 (Roger)
AOB
Reported by Stefano